Connecting rod for a piston of a compressor

ABSTRACT

A connecting rod for a piston of a compressor for a double piston has a portion supportable by a connecting rod bearing on an eccentric of a drive device, a coupling point at a distance from the portion for connecting with the piston, and at least one vibration damping device which in a course of the connecting rod is arranged between the connecting rod bearing and the coupling point.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to connecting rods for pistons of compressors.

[0002] A piston rod of this type in a compressor is conventionally placed between the output of a drive device and a piston or a piston carrier of the compressor, to convert through the connecting rod the rotary, eccentric driven movement of the drive device into a reciprocating movement of the piston. Such an arrangement in a compressor is disclosed for example in the European patent document EP 12 33 183 A1. It has been shown that during the movement process of the piston with the piston and the valves of the compressor, vibrations are generated which are transmitted through the connecting rod and the connecting rod bearing. Further vibrations are generated by the drive device and its eccentric. These vibrations, due to the mechanical loads, can cause premature bearing damages and further have the disadvantage that thereby disturbing noise can be generated, which in particular is unpleasant when such compressors are incorporated for example in vehicles.

SUMMARY OF THE INVENTION

[0003] Accordingly, it is an object of the present invention to provide a connecting rod of the above mentioned general type, which avoids the disadvantages of the prior art.

[0004] More particularly, it is an object of the present invention to provide a connecting rod, which is designed so that when it is mounted in the compressor the vibrations generated in this region are dampened and thereby the produced noise is at least reduced.

[0005] In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a connecting rod for a piston of a compressor for a double piston, comprising a portion supportable by a connecting rod bearing on an eccentric of a drive device, a coupling point provided at a distance from said portion for connecting with the piston; and at least one vibration damping device which in a course of the connecting rod is arranged between the connecting rod bearing and said coupling point.

[0006] When a connecting rod is designed in accordance with the present invention, then because of the at least one vibration damping device which is arranged in the course of the connecting rod between the connecting rod bearing and the coupling point, a very good vibration damping is obtained with the result that the generated noise is reduced many times.

[0007] A compressor with the connecting rod designed in accordance with the present invention is especially advantageous for incorporation where the noise is especially undesirable, for example in vehicles.

[0008] The construction of the connecting rod is simple, cost-favorable and operationally reliable. Due to the obtained vibration damping, an increase of the service life of the bearing can be provided.

[0009] The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a schematic section of a piston with a connecting rod connected with it for a not shown compressor in accordance with one embodiment of the present invention;

[0011]FIG. 2 is a schematic section of a piston with a connecting rod connected therewith, which is substantially similar to FIG. 1, but designed in accordance with another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012]FIG. 1 shows a piston of a substantially not shown compressor, which is provided with a not shown electric high power motor analogous to that disclosed in the European patent document EP 12 33 183 A1, assembled together to form a functional unit.

[0013] The piston 10 is formed as a double piston which has an elongated piston carrier 11. Its one end is provided with a first piston 12 with a greater diameter for a first pressure step and its opposite end it is provided with a second piston 13 with a smaller diameter for a second pressure stage. Due to the design of the piston 10 the compressor is formed as a two-stage compressor.

[0014] The piston carrier 11 together with one of the pistons 12, 13, forms a single-piece component, which can be formed for example as a molded part of synthetic plastic or as an aluminum pressure cast part. The piston 10, in particular its piston carrier 11 is driven by means of a connecting rod 14.

[0015] The connecting rod 14 is rotatably supported on an eccentric 15 at the end of a shaft 16 by means of a bearing 17, for example a ball bearing. The shaft 16 is a part of a drive device in form of a not shown electrical high power motor. The connecting rod 14 extends substantially parallel to the piston carrier 11 and substantially perpendicular to a longitudinal central axis of the shaft 16. In a radial distance from the eccentric 15, a transversely extending pin 18 is fixedly arranged on the piston carrier 11. It is a solid component of the piston carrier 11. It extends from the piston carrier 11 substantially parallel to the longitudinal central axis of the shaft 18 and in direction to it extends so far that the connecting rod 14 by means of a bearing 19, for example a ball bearing, is coupled turnable movable, in particular rotatable. The bearing 19 is supported in the inner ring fixedly on the pin 18, while its outer ring is received non-rotatably in the connecting rod 14.

[0016] The other bearings 17, identified subsequently as a connecting rod bearing 17, extends substantially in the same radial plane as the bearing 19. However, it is radially offset to it, and with its inner ring it seats fixedly on the eccentric 15. In the course of the connecting rod 14 between the connecting rod carrier 17 and the coupling point with the bearing 19, a vibration damping device 20 is arranged. It is provided in the region of the coupling point, for example of the bearing 19, and/or as shown in FIG. 1, in the region of the connecting rod bearing 17. The vibration damping device 20 has a vibration damping bearing receptacle 21 having a vibration damping layer 22. The layer 22 is elastic, and can be formed in particular of rubber, synthetic rubber, etc. The above mentioned damping layer 22 has for example a hardness of substantially 80° Shore A.

[0017] In the shown embodiment shown in FIG. 1, the vibration damping bearing receptacle 21 has a rubber spring, while in another not shown embodiment the bearing receptacle 21 can be formed of the vibration damping layer 22. In this case the connecting rod bearing 17 is embedded with its outer ring directly in the vibration damping layer 22, which in turn is arranged in a receptacle 23, in particular an opening, in the connecting rod 14. In the design of the bearing receptacle 21 as the rubber spring shown in FIG. 1, it has two concentric rings 24 and 25, in particular of metal. A ring-shaped layer 22 is provided between the rings 24, 25. It can be formed for example as a vulcanized rubber layer. By means of the vibration damping bearing receptacle 21 the connecting rod 17 is embedded in the receptacle 23 of the connecting rod 14. The arrangement of the vibration damping device 20 at this location is especially advantageous. The vibration damping layer 22 is designed so that in the peripheral direction it has a greater elasticity than in the radial direction. Preferably in the radial direction it is for example rigid.

[0018] In a not shown another embodiment, the bearing 19 of the coupling point can be embedded by means of a vibration damping bearing receptacle, analogously to the bearing receptacle 21, into the connecting rod 14 and/or in a part of the piston 10, for example of the piston carrier 11.

[0019] Due to the arrangement of the at least one vibration damping device 20, very good damping of vibrations is obtained, which are generated during the movement process of the piston 10 and are transmitted through the connecting rod 14 and the bearings 17 and 19. On the other hand, they are generated by the not shown drive device and eccentric 15. Such vibrations not only load the bearing, but also lead to disturbing noises which are especially undesirable when the thusly formed compressors are used for example in the motor vehicles. Due to the vibration damping device 20, such vibrations in the region of the bearing receptacle 21 are taken by the layer 22 and dampened. Thereby a noise generation is reduced many times.

[0020] In the second embodiment shown in FIG. 2 the parts which correspond to the same parts of the first embodiment are identified with the same reference numerals, and therefore their repeated description is not provided. The second embodiment is different in that in the embodiment shown in FIG. 2 the pin 18 is mounted in an opening 26 of the connecting rod 14, for example is pressed in it. It extends in a transverse direction in the drawings to the left over the connecting rod 14 and to the piston carrier 11. In the region of the coupling point, the bearing 19 is arranged not at as shown in FIG. 1 in the connecting rod 14, but instead in an opening 27 of the piston carrier 11, in which the bearing 19 is held with its outer ring. On the other hand the bearing inner ring is physically seated on the pin 18.

[0021] Also, in FIG. 2, in correspondence with the first embodiment, at least one vibration damping device 20 is arranged in the region of the connecting rod bearing 17. It is formed in the same way as in the embodiment of FIG. 1. Also, in the second embodiment shown in FIG. 2, additionally or instead of it, the bearing 19 of the coupling point can be embedded by means of a vibration damping bearing receptacle 21 in a part of the piston 10, in particular the piston carrier 11.

[0022] It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

[0023] While the invention has been illustrated and described as embodied in connecting rod for a piston of a compressor, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

[0024] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. 

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
 1. A connecting rod for a piston of a compressor for a double piston, comprising a portion supportable by a connecting rod bearing on an eccentric of a drive device, a coupling point provided at a distance from said portion for connecting with the piston; and at least one vibration damping device which in a course of the connecting rod is arranged between the connecting rod bearing and said coupling point.
 2. A connecting rod as defined in claim 1, wherein said vibration damping device is arranged in a region of said coupling point.
 3. A connecting rod as defined in claim 2, wherein said vibration damping device is arranged in said region of said coupling point and in a region of a bearing in said coupling point.
 4. A connecting rod as defined in claim 1, wherein said vibration damping device is arranged in a region of the connecting rod bearing.
 5. A connecting rod as defined in claim 1, wherein said vibration damping device is formed as a vibration damping bearing receptacle.
 6. A connecting rod as defined in claim 5, wherein said vibration damping bearing receptacle is formed as a vibration damping layer.
 7. A connecting rod as defined in claim 6, wherein said vibration damping layer of said bearing receptacle is formed elastically.
 8. A connecting rod as defined in claim 7, wherein said vibration damping layer of said bearing receptacle is composed of a material selected from the group consisting of rubber and synthetic rubber.
 9. A connecting rod as defined in claim 8, wherein said vibration damping layer has a hardness of substantially 80° shore A.
 10. A connecting rod as defined in claim 5, wherein said vibration damping bearing receptacle is composed of a vibration damping layer.
 11. A connecting rod as defined in claim 5, wherein said vibration damping bearing receptacle has a rubber spring.
 12. A connecting rod as defined in claim 11, wherein said rubber spring has two concentric rings composed of metal and a ring-shaped rubber layer provided between said rings.
 13. A connecting rod as defined in claim 12, wherein said ring-shaped rubber layer is formed as a vulcanized layer.
 14. A connecting rod as defined in claim 6, wherein said vibration damping layer is formed so that in a peripheral direction it has a greater elasticity than in a radial direction.
 15. A connecting rod as defined in claim 14, wherein said vibration damping layer is formed so that it is relatively rigid in said radial direction.
 16. A connecting rod as defined in claim 1, wherein said connecting rod bearing is embedded in said connecting rod by means of a vibration damping bearing receptacle.
 17. A connecting rod as defined in claim 1, wherein said bearing of said coupling point is embedded by means of a vibration damping bearing receptacle in a component selected from the group consisting of a connecting rod and a part of the piston. 